08 Paez Liliana

PREPARATION AND CHARACTERIZATION OF TiO2 COATINGS WITH DIFFERENTS DOPANTS ON GLASSTutor: Josef Matoušek: 

PREPARATION AND CHARACTERIZATION OF TiO2 COATINGS WITH DIFFERENTS DOPANTS ON GLASS Tutor: Josef Matoušek Student: Liliana Rodriguez Paez

ObjectivePreparation of titanium dioxide and mixed oxide layers and their comparation with respect to chemical a optical properties: 

Objective Preparation of titanium dioxide and mixed oxide layers and their comparation with respect to chemical a optical properties

MethodProcess sol-gel applied for the preparation of transparent layers on glass: 

Method Process sol-gel applied for the preparation of transparent layers on glass

Components of TiO2 Solution: 

Components of TiO2 Solution Tetra-n-butyl-orthotitanate Precursor Acid Acetic Catalyst Ethanol Solvent Water Acetylacetone For gelation For Peptization

Slide5: 

Mn(NO3)2 . 4H2O 1.88 g (7.5 mmol) CH3COOH 2.57 ml (45 mmol) CH3COOH 0.64 ml (11.19 mmol) C2H5OH 29.80 ml (510 mmol) C2H5OH 7.45 ml (127.5 mmol) Yellow solution Gelation with H2O 7.60 ml (420 mmol) Tetra –n-butyl-orthotitanate 10.21 ml (30 mmol) Process for preparation of TiO2-0.25MnO solution

Slide6: 

Gel Peptization with acetylacetone 3.10 ml (30 mmol) Final solution

Slide7: 

Tetra-n-butyl-orhtotitanate 10.21ml (30 mmol) CH3COOH 2.57 ml (45 mmol) C2H5OH 29.80ml (510mmol) Solution A V2O5 0.17 gr (0.93 mmol) H2O2 Solution B Red solution Process for preparation of TiO2-V2O5 solution

Slide8: 

Red solution Gelation with H2O 7.60 ml(420 mmol) Peptization with acetylacetone 3.10 ml (30 mmol) Final solution

Conditions for preparation of coatings: 

Conditions for preparation of coatings Microscope slide or silica glass substrate In the dip coating process withdrawing at a speed of around 10 cm min-1 3. Drying of films at 80°C for 2 hours 4. The films heated to different temperatures 500-800°C

Slide10: 

Dip Coating

Analyses realized: 

Analyses realized 1. Measuring of the absorbance in UV region. 2. Measuring of corrosion in water 3. DTA a TG analyses 4. XRD analyses

Slide12: 

Measurement of absorbance TiO2 films

Slide13: 

Measurement of absorbance TiO2-MnO films

Slide14: 

Graph of Na+concentration vs time

Slide15: 

DTA of TiO2-MnO gel

Slide16: 

Influence of Time, number of films and temperature on Crystallite form

Slide17: 

Conclusions The TiO2-MnO films present a higher absorbance in UV region than the films of TiO2. The TiO2-MnO films protect the substrate against corrosion if they are exposed to water for a longer time (above 32 hours) The films present good adhesion and good homogeneity on glass substrate. Anatase as the main crystalline form was detected by XRD analysis in the films burned out at the range of 500-700°C. 5. The anatase-to-rutile phase transformation started at 600-700°C.

References: 

References D. Kim, S. Hahn, S. Oh, E. Kim. Materials Letters 3809 (2002) O. Harizanov, t. Ivanova, A. Harizanova. Materials Letters 49 (2001). T. Ivanova, A. Harizanova, M. Surtchev. Materials Letters 3501 (2002). Y. Wang, U. Helmersson. P. Kall. Thin Solid Films 405 (2002) R. Arroyo, G. Cordoba, J. Padilla, V. Lara. Materials Letters 3432 (2001). O. Harizanov, A. Harizanova, T. Ivanova. Solid State Ionics 128 (2000). T. Zhang, A. Weidenkaff, A. Reller. Materials Letters 3429 (2001)